Thanks again to all! After reading the replies, I was convinced to get the Amperior, especially after Xallarap's observations.
I don't want to have the feeling after buying that there was a better option out there. After all, I can spent my money once, so I want to do it right.
But after MT0227's reply I'm not that sure anymore . The DT1350 was (and is still) a serious option for me. I read a lot about them. I think most reviews agreed that the Amperior is more 'fun' to listen to (plus a little punchier bass). Besides that, I read it was a bit hard to get a good seal on your ears with the DT1350.

I am recommending the Amperior despite the price difference. Like I said previously, the sound of the HD25 and Amperior are very similar. However, you can never get the refinement of the Amperior even after all the mods done to the HD25, which also adds to the cost. If you can test them all and compare, that would be ideal. But I am under the impression that you don't have that luxury. If this helps, get the HD25 if you're listening mostly to mainstream music, rock, pop, rnb, electronica, etc., get the HD25. If your music collection contains jazz, classical, etc., in addition to mainstream music, the Amperior is the better choice.

On the other hand, I cannot recommend the DT1350. I cannot get the proper fit on them, but despite not getting a good fit, I still found the mids to be good. However, with the lack of proper fitting, the sound was muffled, distant, and soft overall, lacked the fun factor. But that's just me. My friends think highly of them. And yeah, they are well built and I like how the DT1350 looks. I think it's a very classy looking headphone.

If your music collection contains jazz, classical, etc., in addition to mainstream music, the Amperior is the better choice.

I think if your collection leans toward jazz, classical, female vocals, folk..etc, neither of the Senns are your answer. I can't recommend the Amperiors at a cost of $350 for this type of music at all, sorry.

lluuk.. I highly suggest you do want you can to hear all your options. Not giving the DT1350s a shot because they don't fit on someone else's ears would be a bad decision to make on your part. Honestly, when amped, I think the 1350's cover more territory then either of the Senns and in certain spaces takes things to an entirely different level.

I owned the amperiors for about a week and returned them. I thought at times the mid bass could be a tad bit overpowering. That and the soundstage seemed very narrow and claustrophobic to me. I have not heard the hd25's to compare.

However I have owned the dt1350's for about a month and they are my favorite portable can. The soundstage is far from big but seems more spacious with better detail and clarity. The bass goes quite deep. With nice highs that never get sibilant. I run them straight out of iPhone 5 and I feel it sufficiently powers them but I can hear how an amp could make them even better. I have small ears and have never had a problem with getting the proper seal.

I think if your collection leans toward jazz, classical, female vocals, folk..etc, neither of the Senns are your answer. I can't recommend the Amperiors at a cost of $350 for this type of music at all, sorry.

lluuk.. I highly suggest you do want you can to hear all your options. Not giving the DT1350s a shot because they don't fit on someone else's ears would be a bad decision to make on your part. Honestly, when amped, I think the 1350's cover more territory then either of the Senns and in certain spaces takes things to an entirely different level.

Both headphones are not ideal for those genres. What I am saying is, if it comes down to the Amperior and HD25, the Amperior would be a better choice if one has a more diverse music taste.

And I agree that lluuk must try all his choices first before making a decision. People have different tastes and hear things differently. I for one don't like the DT1350 while MT0227 likes them. Good luck on your hunt sir.

All the positive things about the DT1350 in this Amperior thread make me want to give them a shot again. Hopefully, in the next coming months it would be available.

Xallarap/MT0227, I think you're completely right. I really should listen to all the options carefully before I make a decision. My number 1 mission right now is to find a store where I can give the DT1350 a try. After all the comments in this topic I think both the Amperior and the DT1350 wouldn't be a bad choice in terms of soundquality. Thank you all.

I agree that the HDs and the DTs complement each other very well. I still want to audition the Amperiors and Momentums but my gut tells me that the differences between the Amps and my HDs would be very very subtle. Still very curious though.

I agree that the HDs and the DTs complement each other very well. I still want to audition the Amperiors and Momentums but my gut tells me that the differences between the Amps and my HDs would be very very subtle. Still very curious though.

According to what the Sennheiser rep said (the video is kickin' around in this thread somewhere), you're exactly correct about that. They apprently wanted to maintain a very similar sound signature, but make it a bit easier to drive and refine the enclosure. That's why I wasn't really a buyer when they were at the apple store for full retail, cause early reviews didn't seem to indicate they were worth the premium over the HDs...but if they drop into a nice price point in the next 30 days I'll pull the trigger on them for sure. I love the styling.

They do look pretty classy. It's like the HD25 went out and bought a new tux - went all 007 :P

haha, so true...I can't really tell which I like better, the silver or the blue...do you have a preference? I already have a lot of black gear as it is, but I think if they offered a black version I'd be all over that.